Prehab Before Surgery: Does Getting Stronger First Actually Help?

Prehabilitation is structured preparation before a planned operation. In the research literature it usually combines three things: progressive exercise aimed at the muscles that will be needed afterwards, education about what recovery will demand, and management of the things that slow healing, such as smoking, poor sleep and uncontrolled long-term conditions.

The logic is simple. You come out of surgery weaker than you went in, and the amount of function you have afterwards is measured from wherever you started. A quadriceps muscle that has been avoiding load for a year loses a great deal of its capacity, and the first six weeks after a knee replacement are a poor time to be building it back from a low base.

Prehab is also the point at which the plan for afterwards gets made. Knowing what week four is supposed to look like changes how you interpret week four when you get there.

The trial evidence is strongest around hip and knee replacement, and it is genuinely mixed in a useful way.

A 2025 overview of systematic reviews in the Journal of Orthopaedic and Sports Physical Therapy found that structured prehabilitation reduced complication rates and improved both measured and patient-reported outcomes after hip and knee arthroplasty, with the benefits concentrated in the first six months after surgery. By a year out, prehabilitated and non-prehabilitated groups tend to converge.

A 2025 meta-analysis of randomised trials in knee replacement reached a narrower conclusion: prehabilitation helped postoperative pain and had little effect on length of hospital stay. Effects on knee function were modest.

Put plainly, prehab buys you a faster and more comfortable first six months. It does not change where you end up at a year, and it does not shorten your hospital stay. For most people, a smoother recovery through the hardest phase is worth having on its own terms, particularly if you need to get back to work or to caring for someone.

The targets are the muscles and movements that recovery will lean on hardest:

• Quadriceps strength. The single best predictor of early function after knee replacement. Sit-to-stand from a raised surface, leg extensions in whatever range is comfortable, and step-ups at a height you can control.
• Hip abductors and extensors. These control the pelvis when you walk and are what stop a limp becoming a habit. Bridges, side-lying leg raises, and banded walks.
• Getting up from the floor and out of a chair without hands. Both are needed within days of the operation.
• Upper body pushing strength. Crutches and frames are an arm exercise, and shoulders that have never pushed anything find the first fortnight hard.
• Walking capacity, in whatever form the joint tolerates. Flat ground, a bike, or the pool if the joint is easier in water.

The obvious objection is that the joint hurts, so training it seems perverse. In practice, most people can load painful arthritic joints considerably more than they expect once someone shows them how to pick the range and the resistance. Our hip replacement rehab timeline covers what the training is preparing you for.

• Rotator cuff and shoulder surgery. Range of movement before the operation predicts range afterwards, and the scapular muscles do a large part of the work in early rehabilitation. Getting the shoulder moving and the shoulder blade controlled beforehand shortens the stiff phase.
• Spinal surgery. A 2025 systematic review and meta-analysis of exercise-based prehabilitation before elective spinal surgery found improvements in function and pain, though the trials are smaller and more varied than the joint replacement literature.
• ACL reconstruction. This is the clearest case of the lot. Going into an ACL reconstruction with a swollen, stiff knee and a wasted quadriceps reliably produces a slower and more difficult rehabilitation. Most surgeons now want full extension, minimal swelling and decent quadriceps activation before they operate. Our article on ACL surgery and rehab costs covers the whole pathway.

Most trial protocols run somewhere between four and eight weeks, at two or three sessions per week. Longer is better if you have the time, though the returns flatten, and something is dramatically better than nothing even with three weeks on the clock.

In the last week before surgery, the emphasis shifts from building to arriving fresh and organised:

• Keep moving, and drop the heaviest sessions in the final three or four days.
• Practise the things you will need immediately: getting in and out of bed on the operated side, using crutches on stairs, and the exercises you will be asked to do on day one.
• Set the house up. Move what you use to waist height, sort out a chair you can stand up from, and clear the routes you will walk.
• Sleep. Poor sleep before surgery makes early pain harder to manage, which our article on sleep and recovery in rehab goes into.

A large proportion of people referred for a surgical opinion have not yet had a proper go at loaded exercise. Prehab does double duty here. If you build genuine strength over eight to twelve weeks and the joint feels materially better, that is useful information about whether surgery is needed at all. If you build genuine strength and the joint is unchanged, you go into the operation better prepared and with a clearer conscience about having tried.

That second outcome is worth as much as the first, because the most common regret after a joint operation is uncertainty about whether it was necessary.

The question that arrives most often once a surgery date lands is whether there is any point doing exercises now, when the joint is going to be operated on anyway. It is a fair question with a specific answer. The Horder Centre in Crowborough performs more hip and knee replacements than any other independent hospital in the UK, so a large share of people around Uckfield are on a pathway there, and the gap between the decision and the date is usually measured in months.

What happens in that gap decides a good deal of the early recovery. Quadriceps strength on the day of surgery is one of the better predictors of how quickly you walk unaided afterwards, and it is a modifiable one. Three months of avoiding the leg because it hurts leaves you starting from a low base at exactly the point when starting from a low base costs the most. Three months of controlled loading, chosen so the arthritic joint tolerates it, changes the number you start from.

Structured preparation before an operation and the staged programme afterwards both sit within pre and post-surgical rehabilitation.

Is it safe to exercise a joint that is waiting for replacement?
Yes, within a tolerable range. Arthritic joints respond well to load chosen sensibly. Discomfort during and shortly after exercise that settles within a day is acceptable.

How soon before surgery should I start?
As soon as the decision is made. Four to eight weeks is the usual research window, and more time helps.

Will prehab get me out of hospital faster?
The 2025 knee replacement evidence found little effect on length of stay. The gains show up in pain and function over the following months.

Can I do prehab on my own?
Partly. The general principles are public, though picking the right exercises for an irritable joint and progressing them safely is where an assessment earns its place.

Does prehab mean I might avoid surgery?
Sometimes, particularly where a full course of loaded exercise has never been tried. It is a genuine possible outcome rather than the aim.